Threshold Secret Sharing With Hidden Access Structure Tokens
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing threshold secret sharing schemes are vulnerable to attacks by adversaries who know the threshold number of parties required to reconstruct the cryptographic secret, allowing them to plan and execute successful attacks more effectively.
Innovation Solution
Implementing a cryptographic secret sharing method that generates multiple threshold access structure tokens for each party, where the threshold number is hidden, ensuring that only the authorized subset of parties can reconstruct the secret, while unauthorized subsets cannot, even if they possess the required number of shares and tokens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the threshold number is made public in existing threshold secret sharing schemes, then parties can easily understand and implement the reconstruction requirement, but adversaries can plan and execute attacks more effectively by knowing the minimum number of parties needed to compromise
Solution Approach 1:
The threshold value is extracted from the public information and embedded within the access structure tokens that are distributed to parties. This allows the threshold to be hidden from adversaries while still being functional for authorized reconstruction. The tokens contain encoded access structure information that reveals the threshold only to authorized parties who possess the correct number of valid tokens.
Solution Approach 2:
The patent changes the parameter representation by encoding the threshold value within cryptographic tokens rather than exposing it as a public parameter. The threshold is transformed from a visible numerical value into a hidden structural property of the access tokens, changing how the parameter is stored, transmitted, and verified in the system.
2Reliability
If multiple threshold access structure tokens are generated for each party, then the threshold number can be hidden enhancing security, but the device complexity and computational overhead increase
Solution Approach 1:
The access structure is segmented into multiple tokens distributed to different parties. Instead of one party holding all access information, the complete access structure is divided into fragments embedded in individual tokens. This segmentation enhances security through distribution while the cryptographic design ensures that managing multiple tokens remains feasible through efficient verification algorithms.
Solution Approach 2:
The access structure tokens serve multiple functions: they authenticate party identity, encode the threshold value, enable secret reconstruction authorization, and provide cryptographic verification. This multi-functionality reduces the need for separate mechanisms for each function, thereby limiting the increase in overall system complexity despite the enhanced security features.
Data Source
AI summary
Cryptographic sharing of a cryptographic secret among multiple parties provides a share of the cryptographic secret is generated for each party. Multiple threshold access structure tokens are generated for each party of the multiple parties. The threshold access structure tokens are generated for a party from one or more random token polynomials selected from a finite field based on the numbers of the multiple parties capable of attempting to reconstruct the cryptographic secret. The share of the cryptographic secret and the multiple threshold access structure tokens generated for each party are distributed to the corresponding party. At least a threshold number of the parties can reconstruct the cryptographic secret using the shares of the cryptographic secret and threshold access structure tokens corresponding to at least a threshold number of the parties attempting to reconstruct the cryptographic secret while less than the threshold number of parties cannot reconstruct the cryptographic secret.